Developer replenishing device for copying apparatus

ABSTRACT

In a copying apparatus, a developing tank holding developing fluid receives replenishment from a storage tank through a delivery valve. A roller turning as a function of the passage of copying sheets turns a threaded spindle or screw over a continuous forward path in response to each turning movement of the roller. The threaded spindle moves a plunger translatorily in response to each movement of the roller. The translatory movements accumulate until the plunger reaches a stop position where it opens the valve. After opening the valve the plunger returns to a starting position on the spindle. At least one of these positions is adjustable.

United States Patent Cranskens et a1.

[54] DEVELOPER REPLENISHING DEVICE [21 Appl. No.: 818,701

[301 Foreign Application Priority Data Apr. 26, 1968 Germany; ..,P 17 72 295.1

[52] US. Cl. ..95/89 R, 355/10 [51] Int. Cl. 3/08, 603g 13/10 [58] Field 01 Search ..95/89, 89 L; 355/27, 10

[56] References Cited UNITED STATES PATENTS 3,202,072 8/1965 Limberger ..95/89 3,504,968 3/1970 Matkovich 3,514,203 5/1970 Zerfahs ..355/l0 Primary Examiner-John M. l-loran Assistant Examiner-Kenneth C. Hutchison Attorney--McGlew and Toren [57] ABSTRACT In a copying apparatus, a developing tank holding developing fluid receives replenishment from a storage tank through a delivery valve. A roller turning as a function of the passage of copying sheets turns a threaded spindle or screw over a continuous forward path in response to each turning movement of the roller. The threaded spindle moves a plunger translatorily in response to each movement of the roller. The translatory movements accumulate until the plunger reaches a stop position where it opens the valve. After opening the valve the plunger returns to a starting position on the spindle. At least one of these positions is adjustable.

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SHEET 8 OF 8 m A'r'ron N 7 5 DEVELOPER REPLENISI'IING DEVICE FOR COPYING APPARATUS DESCRIPTION The invention relates to a developing device for copying apparatus operating according to the electrophotographic method. The copying papers to be processed may have a zinc oxide coating, sensitized by charging and provided with a latent picture by exposure. This can be developed by passing through a liquid developer in which the pigments are dispersed. A storage tank is provided for adding a substance to the developer as a function of the passage of copying sheets, and this substance refers particularly to such pigment particles which are added to the carrier fluid of the developer. However, it is also possible to use pigment particles, possibly on carrier particles so that also here pigment particles are added, possibly in connection with the carrier particles.

It must be understood that the pigmentation particles are removed from the developer during the developing because they color the latent picture and this withdrawal of pigmentation particles is made good by the addition from the storage tank.

It is known to make this addition by optically scanning the blacking of an original or a developed picture compared with reference value. Such a device is very expensive. It is also very difficult to scan the whole range of the pattern of the developed copy.

It is also known to operate the delivery value by means of a pivoting lever through a magnet which remains energized so long as a copying sheet passes through acertain section of a copier.

These known devices operate by means of electrical switching elements and specially actuable switch-operating means and require much space for operating the delivery value and for the optical scanning installation.

It is the object of the invention to provide a compact construction whichoperates only mechanically and comprises an adjustment for changing the added-amount as a function of the number of copies.

It is a further object of the invention to provide a device of the kind hereinbefore mentioned wherein the movement of the said element drives a transport mechanism into which engages a plunger for the delivery valve which is carried along. to a switching cam and wherein the transport mechanism has an adjustable stop to which the plunger may be moved back after an operating stroke in-opposition to the transport mechanism.

Such a transport mechanism may be constructed'in many ways, by means of a translatory movement such as in the form of an adjustable crank which carries along the plunger.

In a preferred embodiment of the invention the said element has the form of a shaft rotating through a certain angle for every passage of coping paper and the transport mechanism is a spindle'fitted in the axial direction of the shaft and into which the said plunger engages from one side; at one end of the spindle there is arranged the switching cam rotating with it and projecting over a limited part of the periphery radially towards one side from the spindle. in this manner the spindle is used simultaneously for producing a mechanical stroke of the plunger to operate the delivery valve. Particularly the arrangement of a spindle on a shaft rotating only through a certain angle for every passage of a copying sheet makes it possible to select different numbers of steps for the valve operation with a comparatively short spindle.

Such shafts rotating only through a certain angle have already been proposed, e.g., as switching rollers such as in U.S. Pat. application Ser. No. 726,638, now U.S. Pat. No. 3,552,849.

Such a switching roller equipped with a flattened portion rotates through 360 or a whole multiple, irrespective of the length of the copying sheet for introducing the copying paper from a ready position into a continuously running transport mechanism.

In a preferred embodiment of the invention the switching camhas the shape of a section of a thread and may be brought into engagement with the correspondingly constructed working end of theplunger. This ensures areliable engagement at the moment of the stroke of the plunger and provides with simple means a substantial force for operating the delivery valve.

Obviously thelimit stop is adjustable in the axial direction of the spindle away from-the switching cam. In this way the operating rhythm of the addition of developer may be adjusted according to the number of copies. A further adjustment is possible by making the angle, through which the shaft rotates for every passage of a paper, a variable one.

A preferred embodiment of the invention comprises a carrier crosshead -in which an axial guide for the plunger is pivotably mounted, wherein the pivot is perpendicular to the axis of the spindle and at least one spring is provided which acts in the sense of pivoting the plunger away from the cam and engaging it into the spindle. in this manner the working end of the plunger, cooperating with the valve and near which the pivot is mounted may remain in a certain position, i.e., at the storage tank while the end cooperating with the spindle may be deflected by a suitable amount.

Preferably the carrier crosshead is associated with an adjustable actuating device having an adjusting mechanism for the adjustable-stop and a rigidly connected adjusting device for a pivoting lever the other end of which engages the plunger and raises the same during an adjustment of the stop, particularly in steps against the action of a spring, out of the spindle. In this manner the adjustable stop may be moved in a stepless manner while the plunger follows in steps by intermittently being lifted off the spindle. The adjusting device may be constructed as a crank drive.

In a further preferred embodiment of the invention, however, the adjustable stop is guided after the manner of a slide on the carrier crosshead substantially parallel to the axis of the spindle and the adjusting device has a worm track about an actuating rod as guide means for an actuating pin of the stop. This provides both a ,compact arrangement and an easily changeable positive guide for the adjustable stop.

Preferably the adjusting mechanism comprises a locking plate toothed in a plane perpendicular to the pivoting axis of the lever and whose locking recesses are so dimensioned that when a head of the pivoting lever engages into a recess, the plunger is in engagement with the thread of the spindle, while during the transfer over the section between two locking recesses the plunger is lifted out of the spindle. Thus the distance of the locking recesses may simultaneously be defined the rhythm in which developer is added. Preferably the locking recesses arranged in a periphery of a disc are so spaced relative to the thread of the spindle and the angle of rotation of the shaft that the adjustable stop can be moved as a function of the rotation of the rod only by an amount such that the engaging end of the plunger is movable through a fraction or a multiple of a rotation of the shaft along the switching cam.

To ensure the return of the plunger the same is provided with a spring pawl, extending parallel theretoand adapted to engage during the downward movement of the plunger behind a return stop on the adjustable stop and so recessed at one point that when the plunger rests on the adjustable stop, the

spring pawl releases its upward movement.

In order to disengage the arrangement at choice, the locking plate as a locking recess of smaller depth, in which the plunger is retained out of engagement with the spindle. In this way further additions can be stopped to dilute a developer which has been over saturated with pigmentation particles. An additional manual control may also be provided. It should be noted that the disengagement of the mechanically connected devices requires no coupling or additional actuating member.

The preferred embodiment of the invention consists substantially of a plunger movable towards the delivery valve and pivotable at its remote end wherein the remote end is adapted to be carried along at variable distance from a switching cam in a transport mechanism, in accordance with the passage of paper, wherein the transport mechanism also operates the switching cam in a defined manner.

In a preferred embodiment, the storage tank is mounted vibratable and vertically movably in a housing of the developing device, and the delivery valveis substantially below the operating end of the plunger and has a downwardly springbiased valve body which rests on the actuating pin, fixably mounted on the developing device and passing through the delivery orifice. Owing to the vertically movable arrangement the content of the storage tank is shaken with every operation, ensuring the good mixing of the supply and the uniform flowable condition, as well as preventing a sedimentation of the toner particles.

For. the same reason the delivery valve projects downwardly from the storage tank into a dish through which the developing fluid is pumped causing it to flowpast the delivery arrangement of the delivery valve with its valve body.

According to a further feature of the invention, the delivery valve is a twin valve of which the delivery orifice with the valve body are arranged in the lower wall of the storage tank, and another valve member in the upper wall of the storage tank, the latter being biased by a spring towards the top and closing a venting hole in the top wall of the tank, wherein the actuating end acts on this valve member. In this way venting prior to an actuation of the valve body prepares the release of a metered amount. The venting is of short duration because the valve member is a dual seat valve and opens the venting hole briefly against the spring bias. The metering is further improved by a stop located above the valve body which is mounted in a chamber of the delivery valve and in that the valve body closes the chamber after being lifted off its seat by resting on the stop, thus closing the connection to the interior of the storage tank.

The invention will be further described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatical side elevation of a copying apparatus explaining its functional parts;

FIG. 2 is aside elevation of the device according to the invention, partly broken away;

FIG. 3 is a view of FIG. 2 seen from the right;

FIG. 4 is a view of FIG. 3 seen from the left, on a reduced scale;

FIG. 5 is a view corresponding to FIG. 2, on a reduced scale with the front wall detached and partly in cross section;

FIG. 6 is atop view of FIG. 2 on a reduced scale;

FIG. 7 is a development of a part of FIG. 2;

FIG. 8 is a diagrammatical top view of the developing device without storage tank.

FIG. 9 is a diagrammatical cross section along the line IX- IX in FIG. 8 including the storage tank and the operating end ofthe plunger;

FIG. 10 is a partial view of one end of the storage tank with the delivery valve and a valve operating pin, partly in cross section.

In all drawings identical parts are marked with the same reference numbers.

The copying apparatus of FIG. 1 has on the top 1 a frame 2 under which an original can be passed in the direction of the arrow along an exposure plate 4. The exposure mechanism 5 can be controlled by limit switches 6, 7 which also initiate other functions.

The copying papers are contained in a stack 8. Withdrawing device 9. with a roller 10 on the top sheet of the stack is controlled intermittently by the switches 6, 7 and a switch 11 in the withdrawing device. A roller 12 is flattened and forms a so-called switching roller so associated with a counterpressure roller 13 that that uncut periphery of the switching roller makes engagement with the counterpressure roller. The withdrawing device 9 is stationary when the switch 11 is actuated by an advancing sheet of copying paper and it is released, e.g., when the switch 7 is actuated by an original. The copying paper is transported along the path 14 by continuously revolving rollers along an exposure platform 15 and'through the developing tank 16 through a heating and drying device 17 to a discharge 18. A storage tank 19 with developing substance is mounted above the developing tank. The storage tank has a downwardly opening metering valve the upper end of which can be pushed by a plunger 21. This plunger is mounted in a control mechanism shown generally at 22, described in detail further below extending to the level of the switching roller 12. An operating rod 23 extends from the control mechanism to the top surface .1 for making adjustments for adding developer.

In addition there are provided actuating and control means and connecting means with leads 116 to the switches 6, 7, connecting leads 117 to the exposure light sources 118 and gear connections -123 to the devices to' be actuated, such as rollers, along the paper path 14 and to the control mechanism 22. In the latter the roller 12 revolves once during the delivery of one sheet from the stack 8.

The other drawings show the control mechanism 22 in detail. In FIG. 2 the rotatable actuating rod 23 may be seen, equipped with an operating handle 24 passing from the top surface, as well as the switching roller 12 and the storage tank 19 with the operating end 20 of the delivery valve.

A threaded spindle 25 is mounted nonrotatably on the axial extension of the roller 12 and has its other end located in a bearing 26. This bearing is mounted in a sporting wall 27, shown by dotted lines, extending parallel to the plane of the drawing in FIG. 1, and arranged within the housing 124 on one side thereof.

A carrier crosshead 28 is mounted on the wall 27, e.g., by fixing lugs 29, 30 shown in FIG. 4 and a bearing bracket 31, e.g., via a lug 32 (FIG. 4) possibly by screwing.

The lower end of the actuating rod 23 is located rotatably but not vertically movably in the bearing bracket 31, e.g.,.the thread 32 provided at the lower end of the rod for fixing certain elements may pass through the bracket 31. The lower end 33 may carry a locknut not shown.

Obviously the upper end of the rod 23 may be retained in a hole in the upper surface 1 of the housing (FIG. 1) by means not shown. I

In thesidewalls 34, 35 of the carrier crosshead 28 an axial guide 38 for a plunger 39 is mounted pivotably about one or two pivots 36, 37 extending substantially at right angles to the axis of the spindle 25. The arrangement of the pivots 36, 37 is such that the centerline of the plunger intersects the axis of the spindle 25. The operating end 40 of the plunger can therefore move parallel to the extent of the spindle 25 I FIG. 4 shows that the wall of the plunger guide, which is in front of this drawing, has slots 41, 42, 43 extending perpendicularly to the longitudinal direction of the plunger, and through which engage guide lugs 44, 45, 46. These guide lugs are widened behind the slots and form a parallel guide, which is secured against loss after the installation.

Inside the plunger is a transverse rod 47 serving as abutment for a spring 48 directed obliquely upwardly relative to the top position of the plunger 39 defined by the spindle 25, and hooked at 49 into the carrier crosshead 28. In this manner the plunger 39 is biased both towards the top for engagement into the spindle 25 and in the direction of a pivotable movement in a clockwise sense.

The lower end of the plunger carries through a spring support 50 the operating member 51 forming the lower end 21 of the plunger. The movability of the operating member 51 relative to the plunger makes possible the operation of the delivery valve in two stages.

The upper end 40 of the plunger 39 has a center web 52 which engages into the thread of the spindle 25. In the direction of the pull of spring 48, a step 53 is provided, along which the threads move when the web engages into the thread. A lower step 54 is arranged on the other side of the web 52 so that a switching cam 55 can move past the web 52 prior to engaging the step 53. The switching cam 55 may be kidney shaped, as shown in FIGS. 3 and 4 and extends over slightly more than 180 of the periphery of the spindle 25. FIG. 5 shows in detail that the switching cam follows the shape of a thread. Thus, during the operation of the device when the end 40 of the plunger reaches the switching cam 55 it can engage with its periphery 56 the step 53 and push the plunger 39 in its guide 48 against the spring 48 towards the bottom to operate the element 20. Obviously the switching cam 55 is mounted axially and peripherally rigidly on the spindle 25. The deeper step 54 enables the cam 55 to move past the back of the rod 52 immediately prior to its engagement into the step 53.

An adjusting stop 57 is mounted after the manner of a slide on the crosshead 28 and may be guided on an upper web 79 of a sidewall 34 of the crosshead 28. At the level of an abutment 58 for the high may engage behind an inwardly directed projection on the wall 34, not shown in detail. The lug 58 extends into the path of the plunger 39 or plunger guide 38 when pivoted above the pivots 36, 37.

At the adjusting stop 57 .an arm 59 with an upwardly directed operating pin 60 extends through a hole in the wall 27. This pin engages into an adjusting device 61 rigidly mounted on the operating rod. This adjusting device is disc shaped and has at its lower end a worm track 62 approaching from an inlet 63 at the periphery gradually the center zone. It may be seen that, by rotating the adjusting rod 23, the pin may be moved to and fro across the radius of the disc 61. The radius is so dimensioned that, within the widest limits of adjustment the lug 28 may be retracted so far that the end 40 of the plunger 39 is moved to the right-hand end of the spindle as viewed in FIG. 2.

The actuating rod 23 carries also an adjusting mechanism 64 for a pivoting lever 65, mounted pivotably about a pivot 66 in the crosshead 28. This pivot extends parallel to the pivots 36, 37. The end 67 extending into the carrier crosshead overlies an abutment arranged in the plunger 39. The other end has a downwardly angle abutment 69 which is pulled downwardlyby a spring 70 between the adjacent end of the pivoting lever 65 and the bracket 31.

The adjusting device 64 is disc shaped and has a cylindrical actuating ring 71, the development of which is shown in FIG. 7. On the upper side are locking recesses 72. These recesses have a depth such that, with the abutment head 69 in engagement, the pivoting lever 65 is in a position in which the end 40 of the plunger 39 engages into the thread of the spindle 25. When the operating rod 23 is rotated, the lever 65 is pivoted in an anticlockwise direction on the sections 73 between the recesses 72, as viewed in FIG. 2 so that the plunger 39 is moved against the action of the spring 48 towards the bottom and out of engagement with the spindle 25. In this case the spring 48 can pivot the plunger 39 in a clockwise direction as viewed in FIG. 2 in order to determine a starting position selected by the adjustable stop 57.

The plunger is equipped with a spring pawl 74 which cooperates with a return lug 75 provided on the adjusting stop and extending along the upper part of its guide section. As shown particularly in FIG. 6 it is recessed at 76 immediately in front ofthe lug 58.

As shown more clearly in FIGS. 3 and 4, the spring pawl is bent at its upper end towards the return lug 75 and the latter is correspondingly chamfered at its upper end. The arrangement is such that with the plunger in its top position, i.e., engaging into the spindle 25, the pawl and the return lug can pass each other. When the plunger is pushed down by the cam 55 the bent end of the spring pawl 74 engages under the return member 75. The spring 48 can now pivot the plunger 39 in a clockwise direction as viewed in FIG. 2 without the end 40 engaging into the thread of the spindle 25, until the plunger 39 reaches the lug 58. In this position the pawl 74 can move upwardly through the recess 76 so that the spring 48 pulls the plunger 39 towards the top into engagement with the spindle 25.

When the spindle rotates, the web 52 resting under the action of the spring 48 of the left-hand flanks of the threads, moves gradually towards the cam 55 which may take, according to the adjustment of the abutment 57, one or several rotations of the switching roller 12 so that the operation of the operating end 20 of the delivery valve takes place after one or several revolutions of the switching roller.

It should be stressed that the spring pawl 74 and the return member 75 are so'dimensioned that they move the plunger into a slightly higher position than that corresponding to the lowest position of the operating stroke caused by the cam 55. As shown in FIG. 7, the rim 7] contains also a comparatively shallow locking recess 77 which retains the pivoting lever 65 with the abutment head 69 in engagement, in a position out of engagement with the spindle 25 but still away from the actuating end 25 of the delivery valve.

Preferably the rotation of the operating rod 23 is limited to 360 by a stop on the underside of the adjusting device 64. This stop is associated with an abutment on the bracket 31 not shown in detail.

FIGS. 8-10 show a preferred embodiment of the storage tank, 19 in FIG. 1 in connection with the associated parts of the developing tank shown at 16 in FIG. 1.

The actual developing tank is located in a housing 79. A guide track, also shown in FIG. 1 is arranged at 80 below a cover plate 81 and is accessible from the top through slots 82, 83. Underneath this guide track and underneath the cover plate 81, there is a trough-shaped intermediate bottom 84 underneath which is a chamber 85 containing the developing fluid. From this chamber the developing fluid is pumped by a pumping arrangement 86, indicated diagrammatically, into the guide track from which it flows through an overflow into the recess and back into the chamber 85.

The cover plate 81 has a recess 88, the dimensions of which correspond to those of the storage tank shown at 87 in FIGS. 9 and 10. At both ends of the recess there are supports 89, of which the support 90 is higher than the support 89, in view of the shape of the storage tank 87. In the recess 88 arranged adjacent to the guide track the storage tank 87 rests with one end on the support 89 while its other end, forming a projection 91 is held spaced apart above the support 90, by means described below. A low position of the storage tank is defined by resting the lug 91 onthe support 90.

The storage tank has a discharge valve with a delivery arrangement 92 and a venting arrangement 93, described in detail with reference to FIG. 1 and of which the former projects from the bottom of the storage tank while the latter is arranged in thetop wall of the storage tank.

At the point of the delivery arrangement 92 of the valve, the trough 84 has a recess 94 comprising for example a cylindrical wall 95 and abottom 96. The cylindrical wall is recessed at 97 (FIG. 8) enabling liquid entering the recess to flow off. In the center of the bottom 96 an actuating pin 98 extends upwardly to act as a valve member.

It may beseen from FIG. 10 that the discharge orifice 99 is arranged at the bottom of the delivery arrangement 92. In the zone of this orifice 99 there is a plate 100 with a valve seat 101, defining the discharge orifice and cooperating with the spherical valve body 102. This valve body is located in a chamber 103 which is below the actual storage tank and has, above the valve body, an annular abutment 104, adapted to the shape of the valve body and against which the same rests when it is lifted off the valve seat 100, no seal is required at this point.

A spring 105 is mounted in this chamber, acting on the valve body 102 from the top and urging it on to the valve seat 100. The upper spring mounting 106 has lateral recesses 107 through which developing fluid can flow between the abutment 104 and the valve body 102 into the chamber 103.

When the storage tank is fitted into the recess 88, the upper end of the pin 98, passing through the delivery orifice 99 abuts on the underside of the valve body 102 and retains thereby the lug 91 above the support 90. If the tank is now pushed towards the bottom, e.g., by the operating member 51 forming the working end of the plunger 39, the pin 98 lifts the valve body and opens the delivery orifice so that the content of the chamber 103 can flow into the recess 94. In this arrangement it is essential that at least the valve seat 100 and the lower part of the valve body 102 arewithin the zone of the recess 94 so that these parts are rinsed by fluid flowing through the recess to prevent deposits or encrustations.

lnthis connection it should be stressed that a discharge hole 108 in the trough 84 is so restricted, relative to the pumped I on the edge of the hole 109 when the venting arrangement is actuated by theplunger, providing in practice a dual seat valve which opens the passage through the venting device only for a short duration. Conveniently the plate spring 113 is weaker than the spring 115 so that on actuation by the plunger, first the venting hole is briefly opened and then the discharge orifice opened.

Owing to this arrangement the concentrate is added fro the storage tank in very small amounts. It can also be seen that the actuation causes every time a shaking movement of the storage tank.

We claim: I

1. A copying apparatus comprising tank means for holding a developing medium, storage means for holding replenishing substance for the developing medium, delivery valve means connected to said storage means for supplying the substance to said tank means, advancing means for moving copy material to said tank means, movable mechanical means arranged to perform a continuous motion during passage of the coping material past the mechanical means, transport means engaging said mechanical means for moving mechanically in a single direction over a continuous path during movement of said mechanical means, valve-actuating means movable by said transport means between two positions for actuating said valve means when it reaches one of the positions, return means for moving said actuating means to the other position, said valve-actuating means moving cumulatively toward the one position for each movement of said mechanical means, and adjustment means for adjusting the location of one of the two positions.

2. An apparatus as in claim 1, wherein said valve-actuating means includes a first member engaging said valve means and moving with said transport means and a second member located at the second position for momentarily disengaging said first member.

3. An apparatus as in claim 1, wherein said movable mechanical means engages the copying material and rotates therewith during passage of the copy material, wherein said transport means performs a rotary motion and imparts a translatory motion to said actuating means.

4. An apparatus as in claim 1, wherein said mechanical means engages said copying material and rotates in response to movement of the copying material, wherein said transport means includes a screw device rotating with said mechanical means, wherein said actuating means includes a first member engaging said screw device for translatory movement in response to rotation of said screw device and a second member rotating with rotation of said screw device at one end thereof and striking said first member so as to disengage it from the screw device and actuate said valve means.

5. In a copying apparatus an improved developing device, comprising a developing tank containing the developing medium, a storage tank containing a substance for replenishing the developing medium and arranged on the developing tank, a delivery valve in the said storage tank adapted to be operated to supply the said substance to the developing medium in the said developing tank, wherein the improvement comprises an element arranged in the copying apparatus and moving in conjunction with the passage of copying material, actuating means arranged between the said element and the said delivery valve to move the latter as a function of the movement of the element, and comprising a movable transport device, connecting means between the transport device and the element in order to actuate the transport device in accordance with the movement of the element, wherein the connecting means comprise a plunger engaging on the one hand into the transport device and movable thereby, and connected operatively with the delivery valve, wherein the engagement between the plunger and the transport device causes the transport of the engaging end of the plunger wherein the device comprises a switching cam located in the transport path of the transport device and towards which the plunger is moved, said plunger being actuated by the said switching cam to operate the delivery valve, and an adjusting stop on the transport device provided as guide for the plunger after an operating stroke thereof under the action of the switching cam, while the engagement between the transport device and the plunger is released and the plunger is moved back after the operating stroke opposite the movement of the transport device, said developing tank having a first abutment, a second abutment and a third abutment which is rod shaped, all abutments being provided for the storage tank, the rod-shaped abutment being associated with the delivery valve and acting on a valve body of the delivery valve, and supporting through the delivery valve the storage tank so that it rests with one end on the first abutment and is held with the other end spaced above the second abutment, said delivery valve being arranged substantially under an operating end of the plunger, springs pressing the valve body onto a valve seat, closing thereby the delivery orifice, the pressure of the plunger moving the storage tank positively, while lifting the valve body off its seat and moving the other end of the storage tank into contact with the abutment, whereby the delivery orifice in the valve seat is opened.

6. A device as set forth in claim 5, in which the developing tank has a trough in which the storage tank is arranged on its abutment supports, the trough has a recess, the delivery valve projects from the storage tank into the recess, comprising pumping devices in the developing tank which pump the developing medium from the trough through the recess into the developing tank whereby the flowing developing medium rinses the delivery valve and the valve body.

7. A device as set forth in claim 5, wherein the valve body is spherical and the valve seat comprises a plate on to which the valve body is pressed by the spring means, wherein the valve body and the plate are arranged in a lower wall of the storage tank and a further valve member is mounted opposite in an upper wall, which has an opening through which the said further valve member passes, further spring means being provided urging the further valve member in one direction so that it covers the opening, wherein further the operating end of the plunger is connected with the said further valve member lifting the same off the opening against the said further spring means, in order to open the opening and permit a flow of air, wherein the said further spring means are weaker than the spring means for the valve body so as to open during a movement of the plunger, first the said top opening and then to move the storage tank against the spring means, lifting thereby the valve body and opening the delivery opening, and bringing the storage tank into contact with the second abutment.

8. A device as set forth in claim 5, in which the storage tank has a projection containing the valve body of the delivery valve and the lower end of which has arranged thereon the closing plate with the valve seat, wherein a limit stop is provided in spaced relationship above the closing plate for the valve body and the distance is so dimensioned that, when the valve body has been lifted off the valve seat, it rests against the stop which forms a valve seat between the valve body and the interior of the storage tank, wherein the interior of the storage tank is closed during its downward movement towards the second abutment by the valve body resting against the said stop, and a chamber is formed between the stop and the closing plate which ensures the metering of the amount of the substance to be delivered during one downward stroke of the storage tank.

9. In a copying apparatus an improved developing device, comprising a developing tank containing the developing medium, a storage tank containing a substance for replenishing the developing medium and arranged on the developing tank, a delivery valve in the said storage tank adapted to be operated to supply the said substance to the developing medium in the said developing tank, wherein the improvement comprises an element arranged in the copying apparatus and moving in conjunction with the passage of copying material, actuating means arranged between the said element and the said delivery valve to move the latter as a function of the movement of the element, and a movable transport device, connecting means between the transport device and the element in order to actuate the transport device in accordance with the movement of the element, wherein the connecting means comprise a plunger engaging on the one hand into the transport device and movable thereby, and connected operatively with the delivery valve, wherein the engagement between the plunger and the transport device causes the transport of the engaging end of the plunger, wherein the device comprises a switching cam located in the transport path of the transport device and towards which the plunger is moved, said plunger being actuated by the said switching cam to operate the delivery valve, and an adjusting stop on the transport device provided as guide for the plunger after an operating stroke thereof under the action of the switching cam, while the engagement between the transport device and the plunger is released and the plunger is moved back after the operating stroke opposite the movement of the transport device, guide means for the plunger equipped with a carrier crosshead, pivoting bearings between the guide means and the carrier crosshead, wherein the pivoting bearings have pivots on which the guide means are pivotably mounted and which extend perpendicularly to the axis of the transport device and comprising at least one spring mounted on the plunger and on the carrier crosshead and tending to pivot the plunger in a direction away from the switching cam and causing engagement between the plunger and the transport member.

10. A device as set forth in claim 9 comprising an adjustable actuating arrangement, connecting means between the carrier crosshead and the actuating arrangement, wherein the adjusting stop is movable in the axial direction of the transport device from one limit position near the switching cam into another further removed therefrom, comprising an adjusting device for the adjusting stop to move the same, wherein the said adjusting device is connected with an adjusting mechanism connected to a pivoting lever and comprising further means between the pivoting lever and the plunger in order to lift the plunger against the action of the spring out of the transport device during an adjustment of the adjusting stop.

ll. A device as set forth in claim 10 wherein said transport device includes a spindle wherein the carrier crosshead has guide means extending substantially parallel to the axis of the spindle, the adjusting stop is mounted after the manner of a slide in these guide means and has an operating pin pointing away therefrom, wherein the adjusting device has a profiled worm track into which engages the said actuating pin and an operating rod is rotatably mounted in the said adjusting device so that the adjusting stop can be moved in accordance with the rotation of the operating rod, owing to the engagement of the element arranged in the copying apparatus and moving in conjunction with the passage of copying material, actuating means arranged between the said element and the said delivery valve, to move the latter as a function of the movement of the element, and comprising a movable transport device, connecting means between the transport device and the element in order to actuate the transport device in accordance with the movement of the element, wherein the connecting means comprise a plunger engaging on the one hand into the transport device and movable thereby, and connected operatively with the delivery valve, wherein the engagement between the plunger and the transport device causes the transport of the engaging end of the plunger, wherein the device comprises a switching cam located in the transport path of the transport device and towards which the plunger is moved, said plunger being actuated by the said switching cam to operate the delivery valve, and an adjusting stop on the transport device provided as guide for the plunger after an operating stroke thereof under the action of the switching cam, while the engagement between the transport device and the plunger is released and the plunger is moved back after the operating stroke opposite the movement of the transport device, said adjusting stop having a return stop, the plunger having a spring pawl extending parallel to the plunger and fixed thereto and adapted to engage under the return stop during the downward movement of the plunger under the action of the switching cam, the return stop having a recess associated with a lug, extending in the path of movement of the plunger and arranged in the device, and the spring pawl being adapted to move through the said recess when the lug of the adjusting stop releases the plunger for the upward movement.

13. A device as set forth in claim 10, wherein the adjusting device is a toothed locking disk, the tooth profiles being located in a plane perpendicular to the pivot axis of the pivoting lever, the locking recesses are formed by the toothing of the said locking disk, the pivoting lever has a stop head engaging into the said locking recesses, wherein said transport device includes a spindle comprising further guide means which cause the resilient engagement of the said head into the locking recesses and are connected with the pivoting lever, wherein further the locking recesses have a depth such that they cause, with the head located in a locking recess, such a pivoting of the pivoting lever that they plunger is maintained in engagement with the thread of the spindle, while raised sections are provided between the locking recesses which cause the movement of the head when passing thereover, whereby the pivoting lever moved thereby entrains the plunger and lifts the same out of the thread of the spindle.

14. A device as set forth in claim 13, wherein the locking recesses are arranged on the periphery of a disk and spaced apart in relation to the pitch of the thread of the spindle and the angle of rotation of the shaft during the passage of a sheet of copying material, wherein this relation is such that the ad justing stop is movable in accordance with a rotation of the operating rod by an amount, whereby the cooperating end of the plunger is movable towards the switching cam by a fraction or a multiple of a revolution of the shaft.

15. A device as set forth in claim 13, wherein the locking disk has a locking recess with a smaller depth than that of the other locking recesses and so dimensioned that, when the plunger engages through the pivoting lever into this locking recess it is out of engagement with the spindle.

16. In a copying apparatus an improved developing device, comprising a developing tank containing the developing medium, a storage tank containing a substance for replenishing the developing medium and arranged on the developing tank, a delivery valve in the said storage tank adapted to be operated to supply the said substance to the developing medium in the said developing tank, wherein the improvement comprises an element arranged in the copying apparatus and moving with each passage of copying material, actuating means arranged between the said element and the said delivery valve to move the latter as a function of the movement of the element, a

movable transport device, connecting means between the transport device and the element to actuate the transport device mechanically in a single direction over a continuous path and continuously in response to each movement of the element with the passage of copying material, wherein the connecting means comprise a plunger engaging the transport .device and movable thereby and connected operatively with the delivery valve, wherein the engagement between the plunger and the transport device causes the transport of the engaging end of the plunger, said device comprising a switching cam located in the transport path of the transport device and towards which the plunger is moved, said plunger being actuated by the said switching cam to operate the delivery valve, and an adjusting stop on the transport device provided as guide for the plunger after an operating stroke thereof under the action of the switching cam, while the engagement between the transport device and the plunger is released and the plunger is moved back after the operating stroke opposite the movement of the transport device,

17. In a copying apparatus an improved developing device, comprising a developing tank containing the developing medium, a storage tank containing a substance for replenishing the developing medium and arranged on the developing tank, a delivery valve in the said storage tank adapted to be operated to supply the said substance to the developing medium in the said developing tank, wherein the improvement comprises an element arranged in the copying apparatus and moving in conjunction with the passage of copying material, actuating means arranged between the said element and the said delivery valve to move the latter as a function of the movement of the element, and comprising a movable transport device, connecting means between the transport device and the element inorder to actuate the transport device in accordance with the movement of the element, wherein the connecting means comprise a plunger engaging on the one hand into the transport device and movable thereby, and connected operatively with the delivery valve, wherein the engagement between the plunger and the transport device causes the transport of the engaging end of the plunger, wherein the device comprises a switching cam located in the transport path of the transport device and towards which the plunger is moved, said plunger being actuated by the said switching cam to operate the delivery valve, and an adjusting stop on the transport device provided as guide for the plunger after an operating stroke thereof under the action of the switching cam, while the engagement between the transport device and the plunger is released and the plunger is moved back after the operating stroke opposite the movement of the transport device, said element including a shaft revolving during the passage of a sheet of copying material through a certain angular range and the transport device being a spindle mounted in the axial extension of the shaft thereon, while the plunger has a top part with a web, the width of which is such that it engages the threads of the spindle, the switching cam is arranged at one end of the spindle and extends radially therefrom and revolves therewith, extending over a limited section of the periphery towards one side radially from the spindle, while the plunger has an end portion adapted to cooperate with the cam, engaging therewith during the movement of the plunger towards the cam so as to be actuated to operate the delivery valve. 

1. A copying apparatus comprising tank means for holding a developing medium, storage means for holding replenishing substance for the developing medium, delivery valve means connected to said storage means for supplying the substance to said tank meaNs, advancing means for moving copy material to said tank means, movable mechanical means arranged to perform a continuous motion during passage of the coping material past the mechanical means, transport means engaging said mechanical means for moving mechanically in a single direction over a continuous path during movement of said mechanical means, valve-actuating means movable by said transport means between two positions for actuating said valve means when it reaches one of the positions, return means for moving said actuating means to the other position, said valve-actuating means moving cumulatively toward the one position for each movement of said mechanical means, and adjustment means for adjusting the location of one of the two positions.
 2. An apparatus as in claim 1, wherein said valve-actuating means includes a first member engaging said valve means and moving with said transport means and a second member located at the second position for momentarily disengaging said first member.
 3. An apparatus as in claim 1, wherein said movable mechanical means engages the copying material and rotates therewith during passage of the copy material, wherein said transport means performs a rotary motion and imparts a translatory motion to said actuating means.
 4. An apparatus as in claim 1, wherein said mechanical means engages said copying material and rotates in response to movement of the copying material, wherein said transport means includes a screw device rotating with said mechanical means, wherein said actuating means includes a first member engaging said screw device for translatory movement in response to rotation of said screw device and a second member rotating with rotation of said screw device at one end thereof and striking said first member so as to disengage it from the screw device and actuate said valve means.
 5. In a copying apparatus an improved developing device, comprising a developing tank containing the developing medium, a storage tank containing a substance for replenishing the developing medium and arranged on the developing tank, a delivery valve in the said storage tank adapted to be operated to supply the said substance to the developing medium in the said developing tank, wherein the improvement comprises an element arranged in the copying apparatus and moving in conjunction with the passage of copying material, actuating means arranged between the said element and the said delivery valve to move the latter as a function of the movement of the element, and comprising a movable transport device, connecting means between the transport device and the element in order to actuate the transport device in accordance with the movement of the element, wherein the connecting means comprise a plunger engaging on the one hand into the transport device and movable thereby, and connected operatively with the delivery valve, wherein the engagement between the plunger and the transport device causes the transport of the engaging end of the plunger wherein the device comprises a switching cam located in the transport path of the transport device and towards which the plunger is moved, said plunger being actuated by the said switching cam to operate the delivery valve, and an adjusting stop on the transport device provided as guide for the plunger after an operating stroke thereof under the action of the switching cam, while the engagement between the transport device and the plunger is released and the plunger is moved back after the operating stroke opposite the movement of the transport device, said developing tank having a first abutment, a second abutment and a third abutment which is rod shaped, all abutments being provided for the storage tank, the rod-shaped abutment being associated with the delivery valve and acting on a valve body of the delivery valve, and supporting through the delivery valve the storage tank so that it rests with one end on the first abutment and is held with the other end spaced above the second abutment, said delivery vAlve being arranged substantially under an operating end of the plunger, springs pressing the valve body onto a valve seat, closing thereby the delivery orifice, the pressure of the plunger moving the storage tank positively, while lifting the valve body off its seat and moving the other end of the storage tank into contact with the abutment, whereby the delivery orifice in the valve seat is opened.
 6. A device as set forth in claim 5, in which the developing tank has a trough in which the storage tank is arranged on its abutment supports, the trough has a recess, the delivery valve projects from the storage tank into the recess, comprising pumping devices in the developing tank which pump the developing medium from the trough through the recess into the developing tank whereby the flowing developing medium rinses the delivery valve and the valve body.
 7. A device as set forth in claim 5, wherein the valve body is spherical and the valve seat comprises a plate on to which the valve body is pressed by the spring means, wherein the valve body and the plate are arranged in a lower wall of the storage tank and a further valve member is mounted opposite in an upper wall, which has an opening through which the said further valve member passes, further spring means being provided urging the further valve member in one direction so that it covers the opening, wherein further the operating end of the plunger is connected with the said further valve member lifting the same off the opening against the said further spring means, in order to open the opening and permit a flow of air, wherein the said further spring means are weaker than the spring means for the valve body so as to open during a movement of the plunger, first the said top opening and then to move the storage tank against the spring means, lifting thereby the valve body and opening the delivery opening, and bringing the storage tank into contact with the second abutment.
 8. A device as set forth in claim 5, in which the storage tank has a projection containing the valve body of the delivery valve and the lower end of which has arranged thereon the closing plate with the valve seat, wherein a limit stop is provided in spaced relationship above the closing plate for the valve body and the distance is so dimensioned that, when the valve body has been lifted off the valve seat, it rests against the stop which forms a valve seat between the valve body and the interior of the storage tank, wherein the interior of the storage tank is closed during its downward movement towards the second abutment by the valve body resting against the said stop, and a chamber is formed between the stop and the closing plate which ensures the metering of the amount of the substance to be delivered during one downward stroke of the storage tank.
 9. In a copying apparatus an improved developing device, comprising a developing tank containing the developing medium, a storage tank containing a substance for replenishing the developing medium and arranged on the developing tank, a delivery valve in the said storage tank adapted to be operated to supply the said substance to the developing medium in the said developing tank, wherein the improvement comprises an element arranged in the copying apparatus and moving in conjunction with the passage of copying material, actuating means arranged between the said element and the said delivery valve to move the latter as a function of the movement of the element, and a movable transport device, connecting means between the transport device and the element in order to actuate the transport device in accordance with the movement of the element, wherein the connecting means comprise a plunger engaging on the one hand into the transport device and movable thereby, and connected operatively with the delivery valve, wherein the engagement between the plunger and the transport device causes the transport of the engaging end of the plunger, wherein the device comprises a switching cam located in the transporT path of the transport device and towards which the plunger is moved, said plunger being actuated by the said switching cam to operate the delivery valve, and an adjusting stop on the transport device provided as guide for the plunger after an operating stroke thereof under the action of the switching cam, while the engagement between the transport device and the plunger is released and the plunger is moved back after the operating stroke opposite the movement of the transport device, guide means for the plunger equipped with a carrier crosshead, pivoting bearings between the guide means and the carrier crosshead, wherein the pivoting bearings have pivots on which the guide means are pivotably mounted and which extend perpendicularly to the axis of the transport device and comprising at least one spring mounted on the plunger and on the carrier crosshead and tending to pivot the plunger in a direction away from the switching cam and causing engagement between the plunger and the transport member.
 10. A device as set forth in claim 9 comprising an adjustable actuating arrangement, connecting means between the carrier crosshead and the actuating arrangement, wherein the adjusting stop is movable in the axial direction of the transport device from one limit position near the switching cam into another further removed therefrom, comprising an adjusting device for the adjusting stop to move the same, wherein the said adjusting device is connected with an adjusting mechanism connected to a pivoting lever and comprising further means between the pivoting lever and the plunger in order to lift the plunger against the action of the spring out of the transport device during an adjustment of the adjusting stop.
 11. A device as set forth in claim 10 wherein said transport device includes a spindle wherein the carrier crosshead has guide means extending substantially parallel to the axis of the spindle, the adjusting stop is mounted after the manner of a slide in these guide means and has an operating pin pointing away therefrom, wherein the adjusting device has a profiled worm track into which engages the said actuating pin and an operating rod is rotatably mounted in the said adjusting device so that the adjusting stop can be moved in accordance with the rotation of the operating rod, owing to the engagement of the actuating pin into the worm track.
 12. In a copying apparatus an improved developing device, comprising a developing tank containing the developing medium, a storage tank containing a substance for replenishing the developing medium and arranged on the developing tank, a delivery valve in the said storage tank adapted to be operated to supply the said substance to the developing medium in the said developing tank, wherein the improvement comprises an element arranged in the copying apparatus and moving in conjunction with the passage of copying material, actuating means arranged between the said element and the said delivery valve, to move the latter as a function of the movement of the element, and comprising a movable transport device, connecting means between the transport device and the element in order to actuate the transport device in accordance with the movement of the element, wherein the connecting means comprise a plunger engaging on the one hand into the transport device and movable thereby, and connected operatively with the delivery valve, wherein the engagement between the plunger and the transport device causes the transport of the engaging end of the plunger, wherein the device comprises a switching cam located in the transport path of the transport device and towards which the plunger is moved, said plunger being actuated by the said switching cam to operate the delivery valve, and an adjusting stop on the transport device provided as guide for the plunger after an operating stroke thereof under the action of the switching cam, while the engagement between the transport device and the plunger is released and the plunger is moved back after the opeRating stroke opposite the movement of the transport device, said adjusting stop having a return stop, the plunger having a spring pawl extending parallel to the plunger and fixed thereto and adapted to engage under the return stop during the downward movement of the plunger under the action of the switching cam, the return stop having a recess associated with a lug, extending in the path of movement of the plunger and arranged in the device, and the spring pawl being adapted to move through the said recess when the lug of the adjusting stop releases the plunger for the upward movement.
 13. A device as set forth in claim 10, wherein the adjusting device is a toothed locking disk, the tooth profiles being located in a plane perpendicular to the pivot axis of the pivoting lever, the locking recesses are formed by the toothing of the said locking disk, the pivoting lever has a stop head engaging into the said locking recesses, wherein said transport device includes a spindle comprising further guide means which cause the resilient engagement of the said head into the locking recesses and are connected with the pivoting lever, wherein further the locking recesses have a depth such that they cause, with the head located in a locking recess, such a pivoting of the pivoting lever that they plunger is maintained in engagement with the thread of the spindle, while raised sections are provided between the locking recesses which cause the movement of the head when passing thereover, whereby the pivoting lever moved thereby entrains the plunger and lifts the same out of the thread of the spindle.
 14. A device as set forth in claim 13, wherein the locking recesses are arranged on the periphery of a disk and spaced apart in relation to the pitch of the thread of the spindle and the angle of rotation of the shaft during the passage of a sheet of copying material, wherein this relation is such that the adjusting stop is movable in accordance with a rotation of the operating rod by an amount, whereby the cooperating end of the plunger is movable towards the switching cam by a fraction or a multiple of a revolution of the shaft.
 15. A device as set forth in claim 13, wherein the locking disk has a locking recess with a smaller depth than that of the other locking recesses and so dimensioned that, when the plunger engages through the pivoting lever into this locking recess it is out of engagement with the spindle.
 16. In a copying apparatus an improved developing device, comprising a developing tank containing the developing medium, a storage tank containing a substance for replenishing the developing medium and arranged on the developing tank, a delivery valve in the said storage tank adapted to be operated to supply the said substance to the developing medium in the said developing tank, wherein the improvement comprises an element arranged in the copying apparatus and moving with each passage of copying material, actuating means arranged between the said element and the said delivery valve to move the latter as a function of the movement of the element, a movable transport device, connecting means between the transport device and the element to actuate the transport device mechanically in a single direction over a continuous path and continuously in response to each movement of the element with the passage of copying material, wherein the connecting means comprise a plunger engaging the transport device and movable thereby and connected operatively with the delivery valve, wherein the engagement between the plunger and the transport device causes the transport of the engaging end of the plunger, said device comprising a switching cam located in the transport path of the transport device and towards which the plunger is moved, said plunger being actuated by the said switching cam to operate the delivery valve, and an adjusting stop on the transport device provided as guide for the plunger after an operating stroke thereof under the action of the switching cam, while the enGagement between the transport device and the plunger is released and the plunger is moved back after the operating stroke opposite the movement of the transport device,
 17. In a copying apparatus an improved developing device, comprising a developing tank containing the developing medium, a storage tank containing a substance for replenishing the developing medium and arranged on the developing tank, a delivery valve in the said storage tank adapted to be operated to supply the said substance to the developing medium in the said developing tank, wherein the improvement comprises an element arranged in the copying apparatus and moving in conjunction with the passage of copying material, actuating means arranged between the said element and the said delivery valve to move the latter as a function of the movement of the element, and comprising a movable transport device, connecting means between the transport device and the element in order to actuate the transport device in accordance with the movement of the element, wherein the connecting means comprise a plunger engaging on the one hand into the transport device and movable thereby, and connected operatively with the delivery valve, wherein the engagement between the plunger and the transport device causes the transport of the engaging end of the plunger, wherein the device comprises a switching cam located in the transport path of the transport device and towards which the plunger is moved, said plunger being actuated by the said switching cam to operate the delivery valve, and an adjusting stop on the transport device provided as guide for the plunger after an operating stroke thereof under the action of the switching cam, while the engagement between the transport device and the plunger is released and the plunger is moved back after the operating stroke opposite the movement of the transport device, said element including a shaft revolving during the passage of a sheet of copying material through a certain angular range and the transport device being a spindle mounted in the axial extension of the shaft thereon, while the plunger has a top part with a web, the width of which is such that it engages the threads of the spindle, the switching cam is arranged at one end of the spindle and extends radially therefrom and revolves therewith, extending over a limited section of the periphery towards one side radially from the spindle, while the plunger has an end portion adapted to cooperate with the cam, engaging therewith during the movement of the plunger towards the cam so as to be actuated to operate the delivery valve. 